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I was watching the Rugby World Cup 2015: Samoa vs. Scotland game on television this weekend and noticed this happy baby among the Scottish fans. Kudos to his parents for protecting his hearing!

Repeated exposure to loud sounds leads to hearing damage, and that damage is painless, irreversible and cumulative over your lifetime. The noise level at sporting events is easily in the dangerous zone, well above 85 decibels. Consider these quick facts from Health Canada:

If you are in a noisy environment and someone standing a metre away has to shout to be understood, the sound levels are probably higher than 85 dBA and you are at significant risk for permanent hearing loss if exposed daily for 8 hours or more.

If you are somewhere noisy and someone standing 30 cm away has to shout to be understood, the sound levels are likely higher than 95 dBA and you are at significant risk for permanent hearing loss if exposed daily for 45 minutes or more

If you are in a noisy place and someone has to shout into your ears to be understood (how annoying!), the sound levels are likely higher than 105 dBA and you are at significant risk for permanent hearing loss if exposed daily for 5 minutes or more

My guess is that sound level would be well over 105 dBA at many points in time over the 2.5-hour game.

You probably know that bats and dolphins use echolocation to navigate, but did you know that some blind people use it to mountain bike, play soccer, or navigate cities? They make clicking sounds with their tongues and listen to the returning echoes to sense information about the position, size, shape and texture of objects.

A new study, the first in its field, found that blind echolocators process the clicks and echoes by using brain areas that sighted people use to process visual information. Published recently in the scientific journal PLoS ONE, the study examined brain activity in two expert blind echolocators using functional magnetic resonance imaging scans (fMRI). The Early Blind and Late Blind subjects lost their sight at 13 months of age and 14 years of age respectively. Two non-echolocating sighted subjects were also evaluated for control purposes, matched with the test subjects by sex and age.

The study design required a creative approach to measure brain activity, given that a test subject needs to be completely still to produce a good fMRI scan. To address this, researchers made sound recordings of the subjects’ own clicking noises and played them back while using an fMRI scanner to detect BOLD, or blood-oxygen-level dependent activity.

Surprisingly, when the echolocators listened to test sounds that contained clicks and echoes, compared to test sounds that contained only clicks, researchers measured activity in the subjects’ visual cortex areas known as the calcarine, but not the auditory areas. Lead author Lore Thaler, postdoctoral fellow at The Centre for Brain and Mind at Western University in London, Ontario says, “This was exciting for us! With this comparison, we saw differences in the visual parts of the brain without differences in the auditory. I expected to see brain activity in both the auditory and the visual cortex of the brain.”

Both the Early Blind and Late Blind test subjects showed brain activity in their middle temporal and nearby brain areas when they were listening to sound recordings of moving objects. Those are the brain areas that activate when sighted people view an object in motion. The Early Blind test subject showed more proficiency in distinguishing the angular position of a pole compared to the Late Blind tester, but both were excellent.

Daniel Kish was the Early Blind test subject in Thaler’s study. He is able to mountain bike, navigate in the wilderness alone and can sense a building 1,000 feet away. He founded World Access for the Blind, a non-profit organization with a mission to help blind people learn echolocation so that they can participate and achieve at the same level as sighted people. Daniel and his colleagues have worked directly with over 500 blind students to teach them how to use echolocation.

The World Health Organization estimates that there are 39 million people worldwide who are blind. In the United States alone, there are 937,000 adults over the age of 40 who are blind. Kish says that there are no hard statistics available about how many blind people are using echolocation, but from his experience, “about 50% of blind people may use some form of echolocation to help them interact with the environment.” He continues, “this is usually rudimentary, and they are usually unaware of what they are doing, or how. Perhaps around 5% actually develop an advanced form of echolocation whereby they typically use some form of self-generated sonar signal.”

Thaler says that echolocation can be a useful tool for sighted people, to sense objects in the dark or behind them. She is trying to learn the technique herself, and can sense the difference in objects placed in front of her while blindfolded. She admits that she needs to find an uninterrupted stretch of time to refine her learning.

The basic skills of echolocation can be learned in 2-3 days and refinement takes place over time for each individual. Kish says, “It is a skill much like any other. It definitely takes practice for refinement, and inherent talent does help, but is not required. It is easiest for young ones to learn, but older folks can also learn if they are motivated. Our motto is “the earlier the easier, but it’s never too late.”

Since the study was published, Thaler has received many emails from blind people who have never heard about echolocation before. She hopes that future studies will continue to unravel the mysteries of how echolocation works so that more can learn to live their lives with no limits.

Pardon me? Hearing loss as we age may be common, but difficulty hearing speech in noisy places is one of the most common complaints among healthy older adults, regardless of ability to hear pure tones in an audiogram test. Each May, the American Speech-Language-Hearing Association celebrates Better Speech and Hearing Month, so here are some surprising findings from two recent studies to help you keep your hearing nimble as you age.

Two recent studies found that lifelong musicians have a distinct advantage hearing conversations in busy environments. “Musical experience, actually making music, has a very profound effect on how we process sound. Musicians have lots of practice using auditory working memory that benefits them in all kinds of other communications,” says Nina Kraus, Ph.D. and Principal Investigator at the Auditory Neuroscience Laboratory at Northwestern University.

Kraus recruited two small groups of middle-aged musicians and non-musicians, aged 45-65, and ran a series of tests to measure their ability to hear speech in noisy conditions and their ability to track sound. ‘The musicians had begun musical training before the age of 9, and had consistently played a musical instrument throughout their lives.

Kraus found that musicians were 40% better than non-musicians at hearing speech in noise and were significantly better at recalling what was said a few seconds earlier. Hearing speech in noise correctly requires tracking pitch, timing and timbre, as well as the ability to exclude irrelevant background noises. Kraus’ study was published in PLoS ONE.

A larger, more recent study by Benjamin Zendel, Ph.D. and Claude Alain, Ph.D. at the Rotman Research Institute, University of Toronto, replicated Kraus’ findings. Zendel and Alain found that active musical experience throughout life could help delay speech-in-noise hearing problems by as much as 20 years. Zendel and Alain’s study measured auditory processing abilities among 74 lifelong musicians and 89 non-musicians between the ages of 18-91. The study was released online ahead of publication in Psychology and Aging.

How to help keep your hearing nimble as you age:

Play any musical instrument. Kraus says, “We learn best what we care about. If there is an instrument or a genre of music you care about, that’s the right one for you.” The active creation of music requires both hearing and managing timing–listening and processing what went before and what comes next–in order to exercise and build auditory working memory and speech-in-noise skills.

It doesn’t matter if you play well! Kraus advises that regardless of your ability to play, your hearing ability will improve with practice.

Start young. Research shows that the earlier you start playing a musical instrument the better. Kraus advocates, “Musical education is part of your overall education. It’s not about becoming a violinist or a flautist, it’s about helping children become better learners, better readers and better communicators throughout their lives.”

Is it too late to start when you are older? Kraus says while there is no conclusive proof yet that musical training started later in life can reverse speech in noise difficulties, she has every reason to believe that it’s possible. She recommends playing a musical instrument as the single best thing you can do to improve your hearing.

I love the pumping beat of rock music in my spin cycle class. It keeps me on pace, ensuring a good cardio burn. The instructor cranks up the stereo in the small room that holds 15 bikes, donning her microphone so the class can hear her instructions over the music. It’s a blast, literally.

I’m the keen one, front row centre with my cleats locked into the pedals, ready to grind. But you will notice something else – I’m the only one sporting bright orange foam earplugs.

These accoutrements are certainly not a fashion statement, nor a criticism of the music. After all, I am part of the generation that grew up believing louder is better. I had my first Sony Walkman at age 18 and sure loved to crank INXS to excess.

But now, at 46, I suffer from tinnitus – a buzzing noise I hear 24/7. I also have difficulty focusing on conversation in environments with a lot of background noise. Both are warning signs I have some hearing damage. Even worse, it turns out my favourite fitness activities have the potential to hasten my journey into a silent world. I have twenty years to go before I am a senior citizen. So what’s going on?

The Canadian Academy of Audiology defines tinnitus as “the term used for noises or sounds which are heard in one or both ears which do not come from an external source. They are often described as a high-pitched ringing but can also be described as a buzzing, hissing, pulsing, whistling, roaring, or various other sounds.” As many as 360,000 Canadians suffer from tinnitus. Noise exposure is its leading cause, and the Canadian Hearing Society says that hearing loss is occurring at an increasingly younger age.

Remember as a child trying to hear the ocean by holding a seashell to your ear? That’s what tinnitus sounds like to me, only at a higher pitch, like a cricket. It rings louder at night when everything else is quiet. I’m lucky my personal buzz is not very loud; some people suffer from tinnitus so debilitating it leads to increased stress and, in some cases, depression.

I also have difficulty deciphering specific words when there is a competing noise, such as a kitchen faucet. Before realizing I had symptoms of hearing loss, my husband would accuse me of not listening, whereas to me, it seemed he mumbled. How ironic that my teens ask me to turn down the TV and stereo!

Two things can cause noise induced hearing loss (NIHL): actual sound level, measured in decibels (dBA), and the length exposure to high dBA. The louder the sound, the less time it takes for that noise to damage your hearing. According to Health Canada, if sound levels exceed 95 dBA, there is “a significant risk of permanent hearing loss if you are exposed for 45 minutes or more per day.” At more than 105 dBA, significant risk happens when “you are exposed for just 5 minutes per day.”

Hearing loss is cumulative over your lifetime, and it is permanent. NIHL progresses gradually over time and is painless. By the time you notice symptoms, it is too late to prevent it.

M.J. DeSousa, a Toronto audiologist, compares the effects of noise damage to walking on grass. The first few times, the impressions left by your footprints bounce back easily. But over time, the impressions become permanent and the grass is damaged. Similarly, the little hair cells in your inner ear can withstand some abuse, but over time, they cannot recover and hearing loss results.

DeSousa, 41, suffers from mild tinnitus herself. A busy mom, she can’t believe how high noise levels are at her kids’ recreational events such as swim meets, where even the competitors sometimes miss the sound of the starter’s horn. She helped out as a timer at one event and her own ears were ringing afterwards from too much exposure.

Canadian regulations for workplace safety require employers to provide hearing protection for employees where the noise level exceeds 85 dBA (90 dBA in Quebec). But there are no regulations for exposure to recreational noise levels. In these cases, you have to be your own sound level control board, managing both your exposure and duration.

I’ve been an avid fitness fanatic for the last 20 years, participating in everything from aerobics to Spinning and even the new Latin dance fitness craze called Zumba. The sound level in these classes can be deafening…literally, as it turns out. Exposure for an hour, three or four times a week on a regular basis, can add up to significant cumulative damage.

I measured the sound levels in my classes to find out how loud they really are. In the Spinning class, the sound level ranged between 88 and 95 dBA and shot up to 98 when the instructor hollered some motivation for the last few hill climbs. Zumba measured up to 98 dBA at the back of the room, away from the speakers. A friend came over to talk to me after Zumba finished, and although I was only three feet from her, she was shouting at me as if I were across the room.

Margaret Cheesman, Principal Investigator at the National Centre for Audiology at the University of Western Ontario in London, says that people in the 40-plus age group are experiencing fairly high rates of hearing loss, and thinks that a good deal of it is preventable. A 2001 Canadian Hearing Society survey found that hearing loss affects almost a quarter of people between the ages of 40 and 60. Furthermore, 70 percent of those who claimed to have hearing loss were under 60, with an average age of 51.

Frustrated with my own symptoms, I consulted a certified otolaryngologist, who scheduled an audiology test as well as a precautionary MRI to check for internal structural causes.

Surprisingly, the audiology test results showed that my hearing is still within an acceptable range. The doctor found that my tinnitus and focus issues are likely symptoms of NIHL, stating that I will “just have to learn to live with them.” He suggested I try tinnitus retraining therapy, which takes almost two years to complete and involves listening to audiotapes of varying sound levels and retraining your brain to ignore the phantom tinnitus sounds. TRT takes from 18-20 months to complete. If my tinnitus gets worse, I will consider this.

In the meantime, I take DeSousa’s “daily dose” advice to heart. “We need to think about how much noise we are exposed to in a day from all potential sources,” she advises. “For example, if you blow-dry your hair, then hop on the subway with your iPod turned up, then go to a fitness class later, you may be overdoing noise exposure.”

Cheesman says we need to take responsibility for proper sound levels in our environment. She likes to see people actually ask to have the sound turned down and “not make the assumption that we’re the only ones finding it too loud”. She requests this in her own fitness classes and at the movies, “particularly at the beginning when they are running the trailers which are louder than the movie itself.” She doesn’t mind being the one to ask; she sees lots of others plugging their ears with their fingers.

Cheap foam earplugs available at drugstores are very effective if inserted properly. My earplugs reduce sound by 33 dBA, bringing my fitness class exposure down to a level in the sixties, a safe number for any duration of time. Besides, I can still hear every instruction from the drill sergeant at the front.

The best I can do now is to protect the hearing I still have. I don’t care if I look dorky at the gym with my orange earplugs. I don’t want my tinnitus to get worse; when I’m 65, and I want to be able to hear gentle breezes and the laughter of a grandchild.

How LOUD can you go?

dBA

Sound Source

140

airplane takeoff

110

chainsaw, rock concert

110

MP3 player on max

93

music in fitness class

88

crowded restaurant

60

normal conversation

Steps to Healthy Hearing

Get your hearing tested. See a doctor if you have persistent ringing in your ears or sudden hearing loss.

Practise safe listening. Keep earplugs in your purse or gym bag. Try noise-reducing headphones, and set a volume limit for personal stereos when in a quiet room.

Rest. If you have a ringing sensation or muffled feeling after exposure to noise, this means your ears have been overloaded and need some quiet time to recover.

Advocate. It’s up to you to ask for the volume to be turned down. If you have to shout into someone’s ear to be heard when you are standing right beside her, the sound level is too high.

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